Check valve for intravenous administration of liquids



R. D. COFOID sept. 9, 1969 CHECK VALVE FOR INTRAVENOUS ADMINISTRATION OF LIQUIDS Filed May 8, 1967 A'rrvs.

XNveN'rcR ROBERT D. Cof-01D M1/wl) /MQLAMW Il r United States Patent O U.S. Cl. 137-390 5 Claims ABSTRACT OF THE DISCLOSURE A float-type check valve for use in intravenous administration of liquids. A release Vmechanism is included in the bottom of the check valve for the purpose of forcing the float valve member up ofi its valve seat after the valve has been closed and subsequently attached to a fresh liquid supply vessel. The release mechanism overcomes the forces which normally tend to hold the oating valve element tightly seated due to the suction of a downstream pump or simply due to the column of liquid in the downstream feed tube. The release mechanism is in the form of a plunger slidably mounted in the valve structure adjacent the valve seat so that advancing movement of the plunger unseats the floating valve element from the Valve seat to expose it to the buoying action of the incoming fluid. The plunger may be retracted manually, or by gravitational forces, fluid forces, and/or a biasing spring.

The present invention relates generally to valves for use in intravenous administration of liquids and, more particularly, to an improved check valve for use in intravenous injections.

In the intravenous administration of liquids, a check valve is often used between the solution vessel and the feed line leading to the patient to automatically close the feed line when the supply of liquid is exhausted so as to prevent gas from being injected into the patient. This is especially true where increased pressures are used to increase the rate of injection. A typical check valve used for this purpose employs a float valve member which is buoyed up off a mating valve seat as long as solution is present in the valve chamber, and then descends down onto the valve seat to close the valve when the solution supply is exhausted. While the float type valves are effective in preventing the injection of gas into the patient, it has been found to be difficult to unseat the valve when the exhausted liquid container has been replaced with a fresh container. This is especially true when a pump is connected in the liquid supply line between the check valve and the patient; the pump draws the floating valve member so tightly against the valve seat that it is often impossible to even shake it loose. When a gravity feed system is employed, the floating valve member can usually be unseated by lowering the supply vessel below the float valve, but this is a cumbersome and time-consuming operation.

It is therefore, a primary object of the present invention to provide an improved check valve, suitable for use in intravenous administration of liquids, which closes automatically when the solution supply is exhausted, but can then be reopened by a simple manual operation.

Another object of the invention is to provide such an improved check valve which is simple and economical to manufacture.

It is a further object of the invention to provide an irnproved check valve of the foregoing type which does not interfere with the liquid flow while liquid is being administered intravenously.

Patented Sept. 9, 1969 Other objects and advantages of the invention will become apparent upon reading the following detailed description and lupon reference to the drawings, in which:

FIGURE 1 is a sectional elevation view of a check valve embodying the present invention, in its closed position;

FIG. 2 is a partial section of the same check valve shown in FIGURE 1 with the valve reopened by the release mechanism provided by this invention;

FIG. 3 is a partial section of another check valve embodying the present invention, with the valve in its closed position;

FIG. 4 is a partial section of the same check valve shown in FIGURE 3 with the valve reopened by the release mechanism provided by this invention;

FIG. 5 is a partial section of still another check valve embodying a modified form of the present invention;

FIG. 6 is a partial section of a further check valve ernbodying another modified form of the invention;

FIG. 7 is a partial section of another check valve embodying a further modified form of the invention; and

FIG. 8 is a partial section of yet another check valve embodying a still further modified form of the invention.

While the invention will be described in connection with certain preferred embodiments, it will be understood that it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalent arrangements as may be included within the spirit and scope of the invention as defined by the appended claims.

Turning now to the drawings and referring first to FIGURE l, an intravenous solution 10 is fed from a supply container or vessel such as a solution bottle 11 through a check valve 12 into a feed line 13 adapted to be attached to the patient receiving the solution. In many intravenous administration arrangements, the liquid in the feed line 13 is fed to the patient via a pump (not shown) connected in the feed line between the check valve 12 and the patient. In the illustrative embodiment, the check valve 12 includes a main body cylinder 14 which forms the valve chamber (often referred to as the drip chamber) and is closed at its upper end by a cap 15 forming a longitudinal passageway 16 for admitting the solution into the valve chamber. The cap 15 also includes an elongated projection 17 adapted to fit through a complemental opening in the bottle stopped 18 to receive the solution 10.

As the intravenous solution enters the valve chamber formed by the cylinder 14, a floating valve element 20 is buoyed up off a mating valve seat 21 formed in the upper end of a second valve cap 22 on the lower end of the cylinder 14. As long as suicient fluid is present within the valve chamber to buoy the valve element 20 up off its valve seat 21, a longitudinal passageway 23 extending through the cap 22 remains open so that the fiuid is passed on through the valve structure into the feed line 13. The open position of the valve element 20 is shown in broken lines in FIGURE 1. When the solution supply is exhausted, the valve element 20 descends to its seated position on the valve seat 21, thereby automatically closing the valve to prevent the injection of gas into the patient.

In accordance with the present invention, the check valve is provided with a release mechanism including a release element which is operatively associated with the float valve element at one end and accessible from outside the valve chamber at the other end. In order to release the float valve element from the valve seat, the release element is movable between a retracted position where the 'release element clears the valve seat for seating the float valve element to close the valve, and an advanced position where the release element forces the fioat valve element away from the valve seat to open the valve. Thus, in the illustrative embodiment of FIGURES l and 2, the check valve is provided with a slidable plunger 30 mounted concentrically within the exit passageway 23 and forming a central longitudinal passageway 30a for passing uid from the valve chamber into the feed tube 13. The lower end of the release plunger 30 is provided with a head portion 31 which forms a transverse shoulder 32 adapted to abut the lower end of the valve cap 22 to limit the sliding movement of the plunger. At the upper end, the release plunger 30 forms a head portion 33 adapted to slide within a complementally formed cavity 34 within the valve cap 22 directly beneath the valve seat 21.

In the normal retracted position of the release plunger 30, which is illustrated in FIGURE 1, the upper end of the plunger is positioned below the valve seat 21 so as to permit seating of the float valve element to close the valve. The lower end of the plunger projects downwardly from the bottom of the valve cap 22 so as to be accessible from outside the valve chamber. In operation, the release plunger 30 remains in the retracted position until the exhausted solution vessel 11 has been removed and replaced with a fresh vessel. At this time, the fioat valve element 20 is held tightly against the valve seat 21 due to reduced pressure in the feed line 13 below the check valve; this reduced pressure may be produced by a pump connected in the feed line, or simply by the head of liquid remaining within the feed line 13 at the time the check valve is closed.

In order to release the float valve element 20 from the valve seat 21 to reopen the valve after the fresh supply vessel has been connected to the top of the valve, the release plunger 30 is advanced to the position shown in FIGURE 2 by squeezing the feed tube 13 to move the lower head portion 31 of the plunger up against the bottom of the valve cap 22. This causes the upper end of the release plunger 30 to engage the oat valve element 20 and force it upwardly away from the valve seat 21. As soon as the fioat valve element 20 is released from its valve seat 21, it is buoyed up by the fresh supply of liquid entering the valve chamber from the fresh supply vessel. Thus, it can be seen that a relatively small longitudinal movement of the release plunger 30 is required to reopen the valve, and the release plunger can be retracted almost immediately after it has reached its advanced position, since the buoying action of the yfresh liquid will immediately take over to hold the float valve 20 away from the valve seat 21.

A modified embodiment of the invention is illustrated in FIGURE 3, in which the structure is identical to that illustrated in FIGURES 1 and 2 except that the release plunger 30 is omitted and replaced by a modified release plunger having an outer end accessible from outside the feed tube 13. With this construction, the release plunger is visible outside the feed tube 13 so that the operator does not have to feel for the end of the plunger through the tube. Otherwise, the operation of the release plunger 40 is the same as that described previously for the release plunger 30 in FIGURES 1 and 2; that is, the plunger 40 remains in its retracted position shown in FIGURE 3 until the valve has been closed by seating of the fioat valve element 20 on the valve seat 21, and a fresh solution supply vessel has been connected to the upper end of the check valve. When it is desired to resume the feeding of solution from the fresh vessel, the plunger 40 is advanced to force the fioat valve element 20 up off the valve seat 21, as illustrated in FIGURE 4. In this particular construction, the bottom valve cap 22a is modified to include an inclined hole for receiving the release plunger 40, and the longitudinal passageway 23a through the cap 22a is reduced to about the same diameter as the passageway 30a in the previously described release plunger 30. Of course, the -release plunger 40 must fit tightly enough within the cap 22a to prevent the leakage of fluid therethrough.

The operation of the release plunger 40 illustrated in FIGURES 3 and 4 differs slightly from that of the plunger 30 in FIGURES l and 2, in that retraction of the plunger 40 to permit subsequent reseating of the float valve element is effected manually, whereas retraction of the plunger 30 is effected by a combination of gravitational and fluid forces tending to return the plunger 30 to its lower position as illustrated in FIGURE 1. A modified plunger structure adapted to be retracted in the same manner as the plunger 30, i.e., by a combination of gravitational and uid forces, is illustrated in FIGURE 5. Thus, the plunger in FIGURE 5 includes a plurality of radial ribs 51 forming longitudinal channels therebetween for passing fiuid from the main valve chamber down into the feed tube 13. This construction reduces the friction between the outer surface of the plunger 50 and the inside walls of the cap passageway 23.

In FIGURE 6 there is illustrated a further modified plunger construction adapted to retract the plunger by gravitational forces alone. Thus, the plunger in FIG- URE 6 includes a relatively thin elongated shaft 61 which is seated on the bottom shoulder of the cap cavity 34 by a plurality of integral radial arms 62. It will be appreciated that the cross-sectional area of the plunger 60 is considerably smaller than that of any of the plungers described above, so that it is relatively easy for this plunger to descend through the surrounding liuid due to gravitational forces alone.

As a further alternative, the plunger may be provided with a biasing spring to effect the desired retraction, Thus, in FIGURE 7, a plunger which is identical to the plunger 30 described in connection with FIGURES 1 and 2, is provided with a coiled biasing spring 71 fitted over the exposed portion of the plunger between the lower head 72 and bottom of the valve cap 22. As the plunger 70 is advanced upwardly, the spring 71 is compressed so as to retract the plunger to its normal lowered position as soon as the manual pressure applied by the operator is released therefrom.

Still another modification of the present invention is illustrated in FIGURE 8, in which the release plunger is permanently attached to the float valve element 81. In this case, the upper end of the plunger 80 is closed by its attachment to the valve element 81, so the main shaft OI stem of the -plunger is ribbed or fiuted similar to the plunger 50 described previously so as to permit continuous uid ow therethrough as long as the valve element 81 is buoyed off its valve seat 21. Since it is necessary for both the valve element 81 and the plunger 80 to be buoyed upwardly with this particular construction, both the valve element 81 and the plunger 80 should be made of a material which has a specific gravity of less than 1. If the float member is hollow, of course, it lmay be made of a somewhat heavier material. Since the lower head portion 82 of the plunger 80 abuts the lower end of the valve cap 22 when the valve is open, the lower end of the cap 22 is provided with radial channels 83 to conduct fiuid from the vertical channels in the plunger 80 down into the feed tube 13.

As can be seen from the foregoing detailed description, the present invention provides an improved check valve, suitable for use in intravenous administration of liquids, which closes automatically when the solution supply is exhausted, but can then be reopened by simple manual advancement of a release plunger. The release plunger may be automatically retracted by any one or a combination of gravitational forces, uid forces, or an appropriate biasing spring. The improved check valve is simple and economical to manufacture, and is readily adaptable to high volume production at a low cost. The release mechanism provided in the improved check valve of this invention does not interfere with the liquid flow during intra venous administration so that it does not provide any kind of a safety hazard.

I claim as my invention:

1. An improved check valve for use in intravenous administration of liquids, saidy check valve comprising the combination of means defining a valve chamber, inlet means at the upper end of the chamber for admitting liquid from a supply vessel into the chamber, and exit means at the lower end of the chamber for discharging the liquid into a feed line, a oat valve element disposed within said valve chamber, the lower end of said valve chamber forming a valve seat for cooperation with said oat valve element whereby said exit is opened when said float valve element is buoyed off said valve seat by liquid admitted to the valve chamber and is closed when said float valve element is seated on said valve seat upon eX- haustion of the liquid supply, and a release element comprising a plunger forming a fluid passageway and mounted for sliding movement in said exit between a retracted position where said plunger clears the valve seat for seating said float valve element to close the valve, and an advanced position where said plunger extends into the valve chamber above said valve seat for unseating said oat valve element from said valve seat to Open the valve, said plunger being open at both the upper and lower ends thereof to permit the passage of liquid therethrough when the valve is open.

2. An improved check valve as dened in claim 1 which includes biasing means associated with said release element for biasing said release element toward said retracted position.

3. An improved check valve as dened in claim 1 in which said release element includes a stop means for limiting the movement of said element to determine said advanced and retracted positions.

4. An improved check valve as defined in claim 1 where said release elem-ent is connected to said tloat valve element for movement therewith.

5. An improved check valve for use in intravenous administration of liquids, said check valve comprising the combination of means defining a valve chamber, inlet means at the upper end of the chamber for admitting liquid from a supply vessel into the chamber, and exit means at the lower end of the chamber for discharging the liquid into a feed line, a float valve element disposed within said valve chamber, the lower end of said valve chamber forming a valve seat for cooperation with said float valve element whereby said exit is opened when said float valve element is buoyed off said valve seat by liquid admitted to the valve chamber and is closed when said float valve element is seated on said valve seat upon eX- haustion of the liquid supply, and a release element comprising a hollow plunger mounted for sliding movement in said exit between a retracted position where said plunger clears the valve seat for seating said float valve element to close the valve, and an advanced position where said plunger extends into the valve chamber above said valve seat for unseating said iloat valve element from said valve seat to open the valve, said hollow plunger being open at both the upper and lower ends thereof to permit the passage of liquid therethrough when the valve is open.

References Cited UNITED STATES PATENTS 1,013,695 1/1912 Storer etal. 137-533.11 X 1,643,818 9/1927 Manning 137-390 2,784,733 3/1957 Martinez 137-399 2,964,292 12/ 1960 Noir 251-342 3,205,889 9/1965 Alder et al. 128-214 X FOREIGN PATENTS 628,167 3/1936 Germany.

WILLIAM F. ODEA, Primary Examiner D. R. MATTHEWS, Assistant Examiner U.S. Cl. X.R. 

